The invention pertains to an apparatus for controlling heat flux distributions over the length of the body, such as a torpedo.
The U.S. Navy maintains a research program to improve the speed of torpedoes by reducing drag as the torpedo travels through the water. Drag on a torpedo is increased when the passing water is turbulent. The speed of a torpedo is increased when the passing water is laminar. Accordingly, the Navy has taken several approaches to improve laminar flow. It has been recognized that heat emanating from the exterior surface of any undersea vehicle, such as the torpedo, will directly affect the flow of the passing water. Accordingly, the Navy has supplied heat to the interior of vehicle shells so that the heat flux through the exterior surface will promote the desired laminar flow. In order to obtain the desired controlled heat flux distributions, thin coatings of Teflon, plastic, or other thermally insulating materials have been applied to the exterior surface of the shells. When the coating thickness is varied, the thermal resistance and resulting heat flux are altered accordingly. This approach has had the disadvantage of requiring close dimensional tolerances in order to obtain the prescribed coating thicknesses for the desired heat flux distributions. Another approach has been to vary the dimension of the heat flow passage inside the shell or to vary the number of flow passages therein. While these approaches are practical to fabricate, they do not have enough impact on heat distributions to achieve the desired results of laminar flow.